How light reflects on leaves may help researchers identify dying forests

Trees at UNDERC
Photo Credit: Barbara Johnston/University of Notre Dame

Early detection of declining forest health is critical for the timely intervention and treatment of droughted and diseased flora, especially in areas prone to wildfires. Obtaining a reliable measure of whole-ecosystem health before it is too late, however, is an ongoing challenge for forest ecologists.

Traditional sampling is too labor-intensive for whole-forest surveys, while modern genomics—though capable of pinpointing active genes—is still too expensive for large-scale application. Remote sensing offers a high-resolution solution from the skies, but currently limited paradigms for data analysis mean the images obtained do not say enough, early enough.

A new study from researchers at the University of Notre Dame, published in Nature: Communications Earth & Environment, uncovers a more comprehensive picture of forest health. Funded by NASA, the research shows that spectral reflectance—a measurement obtained from satellite images—corresponds with the expression of specific genes.

Reflectance is how much light reflects off of leaf material, and at which specific wavelengths, in the visible and near-infrared range. Calculated as the ratio of reflected light to incoming light and measured using special sensors, reflectance data reveals a unique signature specific to the leaf’s composition and condition.

Bristol scientists discover early sponges were soft

Xestospongia muta, the barrel sponge, may live for 100 years and grow to over 6 feet tall. While populations have declined at sites throughout the Caribbean, they appear to be quite healthy on Little Cayman Island. Caribbean Sea, Cayman Islands.
Photo Credit: NOAA
(Public Domain)

Sponges are among earth’s most ancient animals, but exactly when they evolved have long puzzled scientists. Genetic information from living sponges, as well as chemical signals from ancient rocks, suggests that sponges evolved at least 650 million years ago. 

This evidence has proved highly controversial as it predates the fossil record of sponges by a minimum of 100 million years. Now an international team of scientists led by Dr M. Eleonora Rossi, from the University of Bristol’s School of Biological Sciences, has solved this conflict by examining the evolution of sponge skeletons.  The research was published in Science Advances. 

Living sponges have skeletons composed of millions of microscopic glass-like needles called spicules. These spicules also have an extremely good fossil record, dating back to around 543 million years ago in the late Ediacaran Period. Their absence from older rocks has led some scientists to question whether earlier estimates for the origin of sponges are accurate. 

A molecular switch that controls transitions between single-celled and multicellular forms

The marine yeast Hortaea werneckii switches between unicellular and multicellular forms depending on food availability. These microscope images show (left to right): individual cells dividing on their own, fully connected multicellular chains that develop directly from single cells, and multicellular forms transitioning back by producing unicellular offspring. This flexibility helps the yeast adapt to changing ocean conditions.
Image Credit: Gakuho Kurita, Sugashima Marine Biological Laboratory, Nagoya University

How did multicellular life evolve from single cells? Nagoya University researchers have identified genes in marine yeast that may help answer this fundamental question. 

Scientists at Nagoya University in Japan have identified the genes that allow an organism to switch between living as single cells and forming multicellular structures. This ability to alternate between life forms provides new insights into how multicellular life may have evolved from single-celled ancestors and eventually led to complex organisms like animals and plants. 

Published in Nature, the study represents an exceptionally detailed molecular explanation of how clonal multicellularity, where all cells descend from a single ancestor, can be achieved and controlled at the genetic level. 

Arctic has entered a new era of extreme weather

Cassiope tetragona killed by a rain-on-snow event.
Photo Credit: R Treharne

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Key Takeaways:

• New research by an international team of scientists has found that Arctic regions are facing unprecedented climate conditions 

• Study has found that extreme weather events have become more common over the past 30 years, threatening plants and animals 

• Findings show hotspots for extreme weather events are Western Scandinavia, the Canadian Arctic Archipelago and Central Siberia 

• Damage from extreme weather can also affect the livelihoods of Arctic people such as reindeer herders and may also harm the ability of the Arctic to absorb carbon and slow climate change. 

Extreme weather events have become significantly more common in the Arctic over recent decades, posing a threat to vital polar ecosystems, according to new research by an international team of scientists. 

Lipid have their own VIP drivers

Image Credit: Scientific Frontline / AI generated

In addition to providing energy, lipids are also essential building blocks of our cell membranes. However, despite their importance, they remain poorly understood. A team from the University of Geneva (UNIGE) has revealed for the first time the secrets of their transport within cells. Each lipid uses a limited number of proteins to move from its place of production to its place of action. The team has also compiled an inventory of the proteins involved in the transport of hundreds of lipids. These findings, published in the journal Nature, provide a better picture of the functioning of our cells, as well as of many genetic and metabolic disorders, such as diabetes and Alzheimer's disease. 

Lipids are often described as our organism's energy reserve, but this definition masks the diversity of their functions. They enable the absorption of some vitamins, are converted into hormones, and assemble into complex membranes. Their dysfunction is also linked to serious diseases such as Alzheimer's, where the lipid composition of nerve cells (neurons and astrocytes) is altered. 

Beyond gene scissors: New CRISPR mechanism discovered

Cryo-electron microscope structure of the nuclease Cas12a3 cleaving the tail of a transfer RNA (tRNA).
 Image Credit: Biao Yuan / Helmholtz Zentrum für Infektionsforschung HZI

The CRISPR “gene scissors” have become an important basis for genome-editing technologies in many fields, ranging from biology and medicine to agriculture and industry. A team from the Helmholtz Institute for RNA-based Infection Research (HIRI) in Würzburg has now demonstrated that these CRISPR-Cas systems are even more versatile than previously thought. 

In cooperation with the Helmholtz Centre for Infection Research (HZI) in Braunschweig and Utah State University (USU) in Logan (USA), the scientists have discovered a novel CRISPR defense mechanism: Unlike known nucleases, Cas12a3 specifically destroys transfer ribonucleic acids (tRNA) that are vital for protein production to shut down infected cells. The team published its findings today in the journal Nature. 

Bacteria contain a wide variety of mechanisms to fend off invaders like viruses. One of these strategies involves cleaving transferring ribonucleic acids (tRNA), which are present in all cells and play a fundamental role in the translation of messenger RNA (mRNA) into essential proteins. Their inactivation limits protein production, causing the infected cell to go dormant. As a result, the attacker cannot continue to replicate and spread within the bacterial population. 

Pills that communicate from the stomach could improve medication adherence

Two photos show the gelatin-coated capsules (left) and the capsule without the coating (right). The capsule can be broken down and absorbed by the body.
Photo Credit: Courtesy of the researchers
(CC BY-NC-ND 4.0)

In an advance that could help ensure people are taking their medication on schedule, MIT engineers have designed a pill that can report when it has been swallowed.

The new reporting system, which can be incorporated into existing pill capsules, contains a biodegradable radio frequency antenna. After it sends out the signal that the pill has been consumed, most components break down in the stomach while a tiny RF chip passes out of the body through the digestive tract.

This type of system could be useful for monitoring transplant patients who need to take immunosuppressive drugs, or people with infections such as HIV or TB, who need treatment for an extended period of time, the researchers say.

Cosmic Lens Reveals Hyperactive Cradle of Future Galaxy Cluster

The galaxy cluster lens J0846 in optical light (bottom right), the ALMA view of dust-enshrouded, star-forming galaxies strongly lensed into bright arcs (top right), and a composite view (left) revealing at least 11 dusty galaxies in a compact protocluster core more than 11 billion light-years away, magnified by the foreground cluster’s gravity.
Image Credit: NSF/AUI/NSF NRAO/B. Saxton; NSF/NOIRLab

Galaxy clusters are formed by a dense packing of many galaxies, making them the most massive structures in the Universe. Their progenitors, protoclusters, show these galaxies in their infancy, offering a window to study how they all formed. This early “settlement” of galaxies will eventually evolve into a sprawling metropolis by the present day. Astronomers using the U.S. National Science Foundation Very Large Array (NSF VLA) and the Atacama Large Millimeter/submillimeter Array (ALMA) have discovered a rare protocluster that was exceptionally bright, all when the Universe was 11 billion years younger. The system, called PJ0846+15 (J0846), is the first strongly lensed protocluster core discovered, revealing how some of the most massive galaxy clusters in the present-day Universe began their lives.

Researchers uncover molecular roots of fibrosis or tissue scarring in inflammatory bowel disease

Spatial mapping of intestinal tissue from patients with Crohn's disease or ulcerative colitis (shown here) allowed the researchers to characterize the cell types (shown as different colored dots) involved in fibrosis. In this image, inflammation-associated fibroblasts that deposit scar tissue roughly align with the cellular niche displayed in royal blue.
Image Credit: Courtesy of the Xavier lab

When inflammation in the body goes unchecked, it can cause fibrosis, or tissue scarring that may lead to organ dysfunction or even failure. This can happen in conditions such as inflammatory bowel diseases (ulcerative colitis and Crohn’s disease), chronic viral infections, interstitial lung fibrosis, chronic autoimmune skin diseases such as scleroderma, and scars associated with heart disease. Patients have few options for treating fibrosis, but new research points to a molecular pathway that could open the door to future treatment possibilities.

In earlier work, a team led by researchers at the Broad Institute and Mass General Brigham discovered a key cell type underlying fibrosis in inflammatory bowel disease (IBD). Now, in a new study in Nature, the team has characterized the crosstalk between this and other types of cells that leads to fibrosis. Their work also points to a molecule, GLIS3, that regulates this cell-to-cell communication and hadn’t been linked to IBD before. The findings suggest that interrupting this cellular pathway could one day help prevent or reduce fibrosis in patients with IBD or other diseases marked by chronic inflammation such as lung disease. 

Natural physical networks are continuous, three-dimensional objects, like the small mathematical model displayed here. Researchers have found that physical networks in living systems follow rules borrowed from string theory, a theoretical physics framework.
Illustration Credit: Xiangyi Meng/RPI

For more than a century, scientists have wondered why physical structures like blood vessels, neurons, tree branches, and other biological networks look the way they do. The prevailing theory held that nature simply builds these systems as efficiently as possible, minimizing the amount of material needed. But in the past, when researchers tested these networks against traditional mathematical optimization theories, the predictions consistently fell short. 

The problem, it turns out, was that scientists were thinking in one dimension when they should have been thinking in three. "We were treating these structures like wire diagrams," Rensselaer Polytechnic Institute (RPI) physicist Xiangyi Meng, Ph.D., explains. "But they're not thin wires, they're three-dimensional physical objects with surfaces that must connect smoothly."